1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/* Compresses a user-specified number of chunks from stdin into stdout as a single gzip stream.
* Each chunk is compressed with a user-specified level.
*/
#define _POSIX_SOURCE 1 /* This file needs POSIX for fileno(). */
#include "zbuild.h"
#ifdef ZLIB_COMPAT
# include "zlib.h"
#else
# include "zlib-ng.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if defined(_WIN32) || defined(__CYGWIN__)
# include <fcntl.h>
# include <io.h>
# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
#else
# define SET_BINARY_MODE(file)
#endif
static int read_all(unsigned char *buf, size_t size) {
size_t total_read = 0;
while (total_read < size) {
size_t n_read = fread(buf + total_read, 1, size - total_read, stdin);
if (ferror(stdin)) {
perror("fread\n");
return 1;
}
if (n_read == 0) {
fprintf(stderr, "Premature EOF\n");
return 1;
}
total_read += n_read;
}
return 0;
}
static int write_all(unsigned char *buf, size_t size) {
size_t total_written = 0;
while (total_written < size) {
size_t n_written = fwrite(buf + total_written, 1, size - total_written, stdout);
if (ferror(stdout)) {
perror("fwrite\n");
return 1;
}
total_written += n_written;
}
return 0;
}
static int compress_chunk(PREFIX3(stream) *strm, int level, int size, int last) {
int ret = 1;
int err = 0;
unsigned long compsize;
unsigned char *buf;
if (size <= 0) {
fprintf(stderr, "compress_chunk() invalid size %d\n", size);
goto done;
}
if (level < 0 || level > 9) {
fprintf(stderr, "compress_chunk() invalid level %d\n", level);
goto done;
}
compsize = 100 + 2 * PREFIX(deflateBound)(strm, size);
buf = malloc(size + compsize);
if (buf == NULL) {
fprintf(stderr, "Out of memory\n");
goto done;
}
if (read_all(buf, size) != 0) {
goto free_buf;
}
/* Provide only output buffer to deflateParams(). It might need some space to flush the leftovers from the last
* deflate(), but we don't want it to compress anything new. */
strm->next_in = NULL;
strm->avail_in = 0;
strm->next_out = buf + size;
strm->avail_out = compsize;
err = PREFIX(deflateParams)(strm, level, Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
fprintf(stderr, "deflateParams() failed with code %d\n", err);
goto free_buf;
}
/* Provide input buffer to deflate(). */
strm->next_in = buf;
strm->avail_in = size;
err = PREFIX(deflate)(strm, last ? Z_FINISH : Z_SYNC_FLUSH);
if ((!last && err != Z_OK) || (last && err != Z_STREAM_END)) {
fprintf(stderr, "deflate() failed with code %d\n", err);
goto free_buf;
}
if (strm->avail_in != 0) {
fprintf(stderr, "deflate() did not consume %d bytes of input\n", strm->avail_in);
goto free_buf;
}
if (write_all(buf + size, compsize - strm->avail_out) != 0) {
goto free_buf;
}
ret = 0;
free_buf:
free(buf);
done:
return ret;
}
void show_help(void)
{
printf("Usage: switchlevels [-w bits] level1 size1 [level2 size2 ...]\n\n" \
" -w : window bits (8 to 15 for gzip, -8 to -15 for zlib)\n\n");
}
int main(int argc, char **argv) {
int ret = EXIT_FAILURE;
int err = 0;
int size = 0;
int level = Z_DEFAULT_COMPRESSION;
int level_arg = 1;
int window_bits = MAX_WBITS + 16;
PREFIX3(stream) strm;
if ((argc == 1) || (argc == 2 && strcmp(argv[1], "--help") == 0)) {
show_help();
return 0;
}
SET_BINARY_MODE(stdin);
SET_BINARY_MODE(stdout);
memset(&strm, 0, sizeof(strm));
for (int i = 1; i < argc - 1; i++) {
if (strcmp(argv[i], "-w") == 0 && i+1 < argc) {
window_bits = atoi(argv[++i]);
} else {
level_arg = i;
level = atoi(argv[i]);
break;
}
}
err = PREFIX(deflateInit2)(&strm, level, Z_DEFLATED, window_bits, 8, Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
fprintf(stderr, "deflateInit() failed with code %d\n", err);
goto done;
}
for (int i = level_arg; i < argc - 1; i += 2) {
level = atoi(argv[i]);
size = atoi(argv[i + 1]);
if (compress_chunk(&strm, level, size, i + 2 >= argc - 1) != 0) {
goto deflate_end;
}
}
ret = EXIT_SUCCESS;
deflate_end:
PREFIX(deflateEnd)(&strm);
done:
return ret;
}
|
